1. Field of the Invention
This invention relates generally to machine tools, and more particularly, to a device for setting the feed amount of a tool or workpiece carrier of a machine tool.
2. Description of the Prior Art
Generally, in grinding machines capable of automatic plunge grinding, it is necessary to set or adjust the grinding feed amount of a wheel head in advance of grinding a batch of workpieces. U.S. Pat. No. 4,086,729 to M. Kikuchi et al. discloses a feed amount setting device of this type, wherein a follower rod is axially slidably supported to follow a cam way formed on a circumferential surface of a rotatable plate cam and is formed at its circumferential surface with an operating face for pivoting a lever arm whose movement is transmitted to actuate a switch element. However, in the known device, the rotation of the plate cam causes the follower rod to displace not only in the axial direction but also in the radial direction due to the presence of an unavoidable play between the follower rod and a receiving bore thereof, and such radial displacement of the follower rod undesirably results in fluctuating the actuation point of the switch element. Moreover, mechanisms which are incorporated into the device respectively for transmitting the pivotal movement of the lever arm to a switch actuation element and for adjusting the relative position of the lever arm to the operating face of the follower rod are complicated in construction and causes an increase of cost.